Spontaneously Reported Adverse Reactions for Herbal Medicinal Products and Natural Remedies in Sweden 2007–15: Report from the Medical Products Agency

BACKGROUND In relation to the extensive use of herbal medicinal products in self-care, the safety information is limited and there is a need for improvement. This study describes spontaneously reported adverse reactions related to herbal medicinal products and natural remedies in Sweden. OBJECTIVES To evaluate the characteristics and frequency of adverse events recorded by the Swedish Medical Products Agency, where herbal medicinal products and natural remedies were suspected as causative agents. METHODS Adverse drug reactions reported to the Swedish Medical Product Agency during 2007-15 related to approved herbal medicinal products or natural remedies were included and analysed in the retrospective study. Reports had been assessed for causality when they were lodged and only reports that had been assessed as at least possible were included in the study. RESULTS In total, 116 reports (concerning 259 adverse reactions) related to herbal medicinal products or natural remedies were found in the Swedish national pharmacovigilance database. The active ingredients most frequently suspected during the study period were black cohosh rhizome (15 reports), purple coneflower herb (14 reports) and a combination of extracts of pollen (13 reports). Adverse reactions related to skin and subcutaneous tissue were the most commonly reported reactions. CONCLUSIONS No previously unknown safety problems have been discovered in the present study. This finding could be explained by a thorough pre-approval assessment of medicinal products and the fact that most herbal preparations in medicinal products have been in clinical use for many years (for traditional herbal medicinal products, the requirements are ≥30 years), i.e. adverse reactions are acknowledged and assessed before approval.